Adaptive pneumatic wing for fixed wing aircraft

ABSTRACT

An adaptive pneumatic wing for a fixed wing aircraft having an airtight envelope ( 8 ) defined by a top skin ( 1 ) and a bottom skin ( 2 ) subdivided internally by a plurality of cells extending longitudinally of the wing, portions of the cells being airtight forming wing structure adapted to provide an aileron function, a landing flap function, and to change the shape of the wing profile.

The present invention relates to a pneumatic, so-called adaptive wing,i.e. inflated by compressed air and modifiable in form by the appliedeffects of compressed air in accordance with the preamble to claim 1.

Pneumatic wings as such have been variously proposed and are known, forexample from two groups of documents:

the first group describes wing structures, which are built up from aplurality of tubular elements: U.S. Pat. No. 3,473,761, U.S. Pat. No.4,725,021 and U.S. Pat. No. 3,957,232;

the wing structures of the other group are kept in shape bydistance-threads and textile straps (so-called “webs”): DE 949 920, U.S.Pat. No. 2,886,265, U.S. Pat. No. 3,106,373 and U.S. Pat. No. 3,481,569.

Pneumatic adaptive wings are not known from the Patent literature.

Pneumatic wings in themselves fulfil a rational technical need only ifthey provide advantages in respect of weight, production costs,simplicity of handling and flight characteristics over other,non-pneumatic, forms of construction and can also be folded innon-operational circumstances; these named advantages do not need to bepresent in all the quoted areas; an overall evaluation should, however,make a pneumatic wing appear advantageous. If we evaluate the documentsin the first group, then a pneumatic wing according to U.S. Pat. No.3,473,761 appears heavy, complicated and expensive to produce and, whichweighs most heavily, is ill suited to solve the static problems of awing. The wing according to U.S. Pat. No. 3,957,232 is—in contrast tothe previous example—constructed of pressure tubes with a large crosssection. The proposed device is however not suitable for creating thenecessary circulation or surface tension in the wing skin, or suffersfrom deformations, which are not shown or mentioned. If, however, onetakes these deformations of the pressure tubes into account, then it canbe seen that the construction is heavy and, in the loaded method ofconstruction, not very stable. In the third description, only a sparstructure is constructed from pneumatic elements; the remainder of thewing receives its shape from sail battens.

The wings or profiles, which are known from the second group ofdocuments, are basically constructed of under and over skins and thestrings or webs which connect the two elements. The solution known fromU.S. Pat. No. 3,106,373 differs from the others in so far as the wholewing envelope comprises an airtight distance web, which is bent andglued into the required shape. The problems of this group comes out mostclearly from DE 949 920.

The wing profile is there symmetrical. The necessary aerodynamic lift(c_(A)) for a wing—whether it be a carrying wing or rotor blade—can onlybe generated by the adjustment angle. The wing profiles shown in theother publications in no case assume the shapes represented underpressure: in the region where strings or webs terminate in the wingskin, pressure and tensile forces act together and give the wing skinits final shape. Especially the profile known from U.S. Pat. No.2,886,265, but to a certain extent the others also, essentially assumeunder pressure the shape known from DE 949 920, with disappearing c_(A).Added to this a pneumatic wing is poorly suited for the attachment ofcontrol cables or rods, especially for moving the aileron. All theproposed ailerons are entirely copied from those of rigid wingstructures and do not represent any technical advance.

What is lacking in all the quoted documents is the intrinsic technicalknowledge of how to produce the overall profile, which poses thequestion as to whether such profiles were ever built, not to mentionwhether they were then flown.

The problem which is to be addressed by the present invention, exists onthe one hand in the production of a pneumatic wing with a prescribedprofile and a predetermined lift coefficient c_(A), with an attachedpneumatic aileron which avoids control wires or rods, and on the other,the wing profile, as a whole or in part, should be modified andoptimised with respect to the flight speed by the application ofelements inflated with compressed air. The usable speed region is thusincreased overall.

The solution of the task set is addressed in the characterising part ofpatent claim 1 with regard to the main characteristics of the device, inpatent claims 2 to 26 regarding further advantageous and identifyingcharacteristics: the invention is more closely described using theattached drawings.

Shown are

FIG. 1 a first section running essentially in the direction of the airflow through a non-adaptive wing in accordance with the invention,without the aileron area,

FIG. 2 the same section as in FIG. 1, however in a second example ofconstruction,

FIG. 3 an important step in the production of the wing with smallchanges to the wing profile per unit of length in the longitudinal axis,

FIG. 4 the process shown in FIG. 3 with a greater change of the wingprofile per unit of length in the longitudinal axis,

FIG. 5 a section through a cell of the wing,

FIG. 6 a longitudinal section through a cell with an advantageousfurther development,

FIG. 7 a first section through the trailing edge of the wing in theneutral position,

FIG. 8 a second section through the trailing edge of the wing in anupwards setting,

FIG. 9 a section through the trailing edge of the wing in anasymmetrical construction,

FIG. 10 a detail of a modification of FIG. 7, 8 or 9,

FIG. 11a,b an overall adaptive wing without the aileron area,

FIG. 12 a further modification of the operation of the aileron,

FIG. 13 a modification of FIG. 2.

FIG. 1 shows a section running in the direction of the air flow througha wing in accordance with the invention, but not, however, adaptive.This has an airtight skin, divided into upper skin 1 and lower skin 2.Between them run a plurality of textile webs 3, which, for instance,comprise webbed material with little extensibility; aramid threadwebbing may be cited as an example of material, although newer hightensile and low stretch materials are now appearing on the market. Thetextile webs 3 permit the passage of air and can, for more rapidequalisation between the cells formed by them, even have holes. On theother hand individual cell webs 3 can be made airtight, so that anyaccidental loss of pressure does not affect the whole wing. The hollowbody formed from the upper and lower skin 1, 2 and the textile webs 3 isflat in its non-inflated condition and can be easily folded or rolled.In the inflated condition it assumes the shape shown schematically inFIG. 1, whereby the upper and lower skins 1, 2 obviously swell outbetween the webs 3, as is more closely described under FIG. 5.

The peripheral or tensile stress σ_(z) of the upper and lower skin 1, 2is determined by the heights H of the webs 3, since for any point on thewing${{\sigma_{z} \approx \frac{\Delta \quad {{pH} \cdot L}}{2L}} = {\frac{\Delta \quad {p \cdot H}}{2}\quad {applies}}},\begin{matrix}{{{where}\quad L} = {{Length}\quad {of}\quad {the}\quad {web}\quad {in}\quad {question}}} \\{{\Delta \quad p} = {{Internal}\quad {pressure}\quad {in}\quad {the}\quad {{wing}.}}}\end{matrix}$

From this it is obvious, that the stress σ_(z) reduces with loweringwing thickness, thus on the leading and trailing edges 4, 5, eventuallybelow a value which can be used for the stability and carrying power ofthe wing.

FIG. 2 shows a measure in accordance with the invention, by which thisfact can be opposed: at a certain distance from the leading and trailingedges 4, 5 an airtight web 6, 7 is introduced, which allows that part ofthe wing which lies in front of the web 6 and that behind the web 7 tobe subject to a greater pressure Δp₂ than the central part of the wing,which is subject to pressure Δp₁, as is shown in FIG. 2. Obviously it ispossible for each cell defined by the web 3 to be inflated with its ownpressure, which requires airtight webs 3. This however requiresindividual compressed air supplies for the individual cells.

FIG. 3 is a first representation of the production process for thedetermination of the position and attitude of the webs 3. This isapplied in wings or wing sections, in which the profile variation perunit of length in the direction of the wing axis is relatively small orabsolutely nil. In order to keep the drawing simple, many fewer webs 3are included than are in fact necessary. If the target profile of thewing is—in several sections analog to the representation in FIG.1—determined by the sought after flight characteristics, then thisresults in a wing envelope 8. In this a family of locus circles 9 can beinserted, which touch the upper and lower skins 1, 2, i.e. the envelope8, at each of two points 10, 11. The points 10, 11 obtained in this wayare—in the profile section under consideration—the attachment points ofthe webs 3. In accordance with the invention this has the effect thatthe wing, when under pressure actually assumes the intended shape but inthe slack condition is prepared for processing, since the angle betweenthe web 3 and the envelope 8 is the same at both of the points 10, 11.Thereby the resulting force components both in the upper and lower skins1, 2, and also in the web 3 under consideration are always essentiallythe same as mirror images. Because of the construction of the webs 3 inFIG. 3 the coordinates of the points of contact 10, 11, which are at thesame time the contact points on the envelope 8 with the level of thewebs 3 can be exactly calculated. In the same way the heights H of thewebs 3 are known. From this can be constructed both the dimensions ofthe fabric web used for the webs 3, and also the positions of the linesalong which the webs 3 should be attached to the envelope.

If an already airtight weave is used for the envelope 8, the lines ofsewing are then sealed with a plastics material which is self binding tothe plastics material to be sealed. If the envelope 8 is only sealedafter the sewing of the webs, then this occurs for instance inaccordance with known processes of plastics lamination of wovenmaterials.

At the position of a sewn joint it is possible according to theinvention to use welding also. There are several modifications foreseenhere:

Either the textiles used are directly weldable; the webs 3 are then forinstance bent over by about 90° at their upper and lower edges and thestrips thus formed are welded to the upper and lower skins 1, 2thermally or using ultrasound. If on the other hand the textilematerials cannot be welded directly, then the above mentioned strips,formed by bending over, can be coated with plastics material beforebending and then welded, using one of the named processes, to thepreviously plastics laminated upper and lower skins 1, 2.

A third modification according to the invention comprieses of not onlypreparing the web 3 in the manner described, but also providing theupper and lower skins 1, 2 with plastics strips and then welding thewebs 3, using these strips. Finally the whole envelope is laminatedairtight.

FIG. 4: If a complete wing or even only a part of one shows a stronglychanged profile in the longitudinal direction, then the process of FIG.3 has to be modified. If the sought after profile is given, then forinstance lines of attachment 25 are established for the textile webs 3on the upper skin 1, corresponding to the necessary bending stiffness ofthe wing.

Then locus spheres 26 are inserted, which touch the attachment line 25and the lower skin 2 simultaneously. The family of points of contact ofthe locus spheres 26 to the lower skin 2 gives the lines of attachmentto the lower skin 2 designated with the reference 27.

FIG. 5 is the schematic representation of a cell 12—essentiallyextending over the length L of the wing—formed by the upper and lowerskins 1, 2 and two adjacent webs 3. If the wing volume is put underpressure, then the upper and lower skins 1, 2 swell out, as alreadystated. These swellings out have the form of a circular arc with radiusR, which is determined by the height H of the webs 3 and their distanceapart B. In so far as the material of the weave used has only a small;force-dependent extensibility, the height ΔH of the swelling isdependent only on H and B, and not on the pressure Δp, as long as Δp>0,for the reason that the pressure exerted on the upper and lower skins 1,2, and also the tensile stress on both, depend linearly on the pressureΔp. For the stability and carrying capability of the wing, on the otherhand, the tensile stress in the webs 3 is decisive. If a wing accordingto the invention is loaded with the generated lifting forces, then thesebending moments operate in the wing root, which essentially reduce thetensile stresses in the upper halves of the webs 3 in the direction ofthe wing, but however increase them in the lower halves. Whilstexceeding a certain maximum stress in the lower halves of the websaffects the limits of the tensile strength of the material, the loss oftension in the upper halves of the webs 3 leads to collapse of the wing.The resistance to collapse is proportional to the pressure Δp anddependent on the height H and the width B of the cells 12.

It is therefore provided in accordance with the invention, that thewidth B of the cells 12 is reduced with decreasing wing height H, to theextent that the width B of the cells 12 is essentially proportional totheir height H. As an advantageous development, the inclusion of the twoairtight webs 6, 7, according to FIG. 2 or FIG. 13 is considered, whichpermits, in the regions of reduced tensile stress in the envelope 8, thepressure Δp to be increased, so as to increase both the stability andalso the carrying power of the wing.

FIG. 6 shows an advantageous development of a web 3 in the longitudinaldirection of the wing; the wing tip is to be imagined to the left, andthe wing root to the right. Over the whole length of the web 3 thenon-stretching weave used—designated by the reference 13—is assembled sothat the run of the threads is on the one hand in the longitudinaldirection and, on the other perpendicular to it: The tensile stresses inthe webs 3 are thus directly generated by the forces workinghorizontally and vertically. Near to the wing root the tensile stresses,as detailed in FIG. 4, increase in the lower part of the webs 3, anddecrease in the upper. The fabric 13 is supplemented here by a second,similarly non-stretch fabric 14, whose direction of threads is turned,for instance, by 45° against that of the first fabric 13. In the area ofthe second fabric 14 there is a break 20 shown in the drawing, in whichthe first fabric 13, lying behind it, is made visible. This arrangementpermits an improvement in the exchange of tension between the verticaland horizontal directions and prevents the possible overloading of thelower edge of the webs.

Within the scope of the development according to the invention it isalso possible to apply two or more layers of the first or second fabric13, 14.

FIG. 7 shows in schematic manner the formation of the trailing edge ofan adaptive wing. From a cell, marked here with reference 15, both theupper skin 1 and the lower skin 2 are covered by a second skin,designated here 16, 17. These are sewn to the upper and lower skins 1, 2in each case somewhat in the centre of the width B of the cell 18following cell 15. Thereby, channels 19 arise over the breadth of theaileron somewhat in the form shown in FIG. 10, whereby it must be takeninto consideration that the height ΔH of the swellings is muchexaggerated in the representation.

If the pressure in the cells 18 is of the magnitude Δp, then that in thechannels 19 is essentially of the same magnitude. Thereby the upper andlower skins 1, 2 are deformed into somewhat of a straight line zig-zagin the region of the cells 18 and only the double skins 16, 17 exhibitarc-formed swellings. If then the pressure Δp₂ in the channels 19 underthe double skins 16, 17 is increased, such that Δp₂>Δp₁, then theswellings in the double skins 16, or 17, enlarge, and swellings arise inthe zig-zag stretched upper skin in the direction of the cells 18. Thechannels 19 are thereby thickened, and—due to the low extensibility ofthe fabric used—shortened in the direction of the air flow, whereby thewing assumes the shape shown in FIG. 8 in the region of the cells 18. Inorder to increase the effect the pressure Δp₃ in the channels 19 on theunderside of the wing can be lowered, such that

Δp₂>Δp₁>Δp₃.

if the quoted pressures are however adjusted such that

Δp₂<Δp₁<Δp₃,

then the swelling of the wing occurs towards downwards.

This configuration of the wing, characterised using FIG. 7, 8, canencompass only a part of or the entire span of a wing. The number ofcells 18 affected by this feature is in any case dependent on theselected characteristics of the wing.

In a modification depicted in FIG. 9 the lower double skin 17 extendsover more cells 18 than the upper double skin 16. The shape of the wingand thus the c_(A) value can thereby be changed over a wider range, byincreasing the pressure in the lower channels 19. This alsochanges—solely by the modification of the trailing edge—the optimumspeed range of the wing. It is similarly in accordance with theinvention to extend the formation of the wing according to FIG. 9essentially over the whole under side of the wing, if need be inconjunction with a further shape changing facility, such as is shown inFIG. 11a, b.

The formation of the wing according to the invention as in FIG. 7, 8 or9 is also suitable, if necessary with a reduced number or locallylimited distribution of the channels 19, as an aileron. If the channels19 extend essentially over the whole half-wing, then the ailerondisplacement required for a given banking of the aircraft can bereduced.

FIG. 10 shows a modification of the construction of the channels 19described; only one channel 19 is shown as an example; the remainder areconstructed similarly. In the channel 19, formed by the space betweenthe upper skin 1 and the upper double skin 16 is inserted a thin walledtube 21 made of elastomer. This tube is closed at its ends; in thisinstance the pressure tube 22 opens into the channel 19 at the endnearest the wing root. Obviously the pressure tube 22 can be introducedinto the elastomeric tube 21 at several locations, so as to acceleratethe change of pressure. If the modification shown in FIG. 10 isselected, then the sealing of the upper and lower double skins 16, 17becomes unnecessary because the sealing function is now taken over bythe elastomeric tube 21.

Instead of wires or rods, in this method of construction as describedthe aileron pressure tubes 22 lead to the wings—directly into thechannels 19. Control can be exercised conventionally, for example bymeans of a control column and—in the modification according to FIG. 9—bya landing flap operation, not however effected by a tensile force incontrol wires, but a change of pressure in the channels 19.

FIG. 1a, b are representations of an overall adaptive wing. Here thetextile webs 3—whose number is reduced in the drawing—each has a channel28. These channels 28 are constructed similarly to the channels 19 inaccordance with FIG. 7, 8, 9 or as pockets 29, as are described underFIG. 10. The under side of the wing is formed as shown in FIG. 9.

In FIG. 11a the channels 19 on the underside of the wing are at highpressure with respect to the inside of the wing, the channels 19 in thewebs 3 are almost pressure free or only supplied with pressure to theextent that the webs 3 do not experience any shortening.

If now the pressure in the channels 19 in the webs 3 increases, then theheights of the webs 3 reduce and the whole wing becomes flatter, asshown in FIG. 11b. The change in shape can also be controlled by thesize of the channels 19 in the webs, as well as the pressure; inprinciple each of these channels 19 can be inflated by an individualpressure. If however only a single pressure is to be used, then the sizeof the channels 19 is the only parameter of the height changing of theprofile.

Due to the shortening of the webs the swelling of the wing is howeveralso changed. So as to compensate for an enlargement of the swelling,the channels 19 on the underside of the wing can be released frompressure. In this way the wing becomes smaller with a controllablechange of the swelling.

The trailing edge is not shown in FIG. 11a, b. It can be configuredaccording to the representation in FIG. 7. Instead of the versionaccording to FIG. 7 it is however possible—in each example ofconstruction—to foresee a configuration according to FIG. 12.

The wing is constructed here from two initially separated parts, acarrying wing 31 and an aileron 32. The two parts 31, 32 are joined, forinstance by welding or gluing—by the outer regions of two cells 33, 34,however over the entire width of the aileron 32. The cells 33 border thecarrying wing 31 to the rear, the cells 34 border the aileron to thefront. It is assumed that the pressure in cell 33 is higher than that incell 34 because of the static function of the carrying wing 31. Thecarrying wing 31 and the aileron 32 are joined by two flat actuators 35,36, which are in principle built and dimensioned identically. Theconstruction of each actuator 35, 36 comprises in each case a doubleskin 37, 38, with airtight channels 19, which arise between longitudinallines 39, along which the double skins 37, 38 are joined. In the neutralposition of the aileron 32 both actuators 35, 36 are inflated, so thatan average shortening occurs. This has the effect that the aileron 32 isdrawn towards the end of the carrying wing 31 and, due to the differencein pressure between the parts 31, 32, the embaying of the cells 34occurs as shown.

If the aileron has now, for instance, to be pivoted upwards, then thepressure in the upper actuator 35 is increased and that in the loweractuator 36 is decreased. Actuator 35 is thereby shortened, actuator 36lengthened, which results in the intended deviation of the aileron.

It is important to the invention that the actuators 35, 36 are eachjoined along a line to the carrying wing 31 and to the aileron 32 andexert line related forces. Instead of the actuators 35, 36 shown in FIG.12, other line force generating actuators meet the desired objective.

A modification to the example of construction according to FIG. 2 isshown in FIG. 13. The example of construction according to FIG. 2operates with a prescribed difference of pressure between leading andtrailing edges 4, 5 on the one hand and the that part of the wing lyingbetween them on the other. In this the swelling of the webs 6, 7 andalso their chords can be determined, so that the wing assumes theprescribed shape. If however the pressure in the leading edge 4, thecentre section of the wing and the trailing edge 5 must remain variable,then the modification shown in FIG. 13 is to be preferred. Here only theairtight web 6 in the leading edge is shown. The construction for thetrailing edge is completely analog. The airtight web 6 is dimensionedsuch that it forms part of that locus circle 9 away from the nose of thewing, which is to form the separation from the leading edge 4 and thecentre section of the wing. Then the airtight web 6 is penetrated by airpermeable webs 3. The jointing of the web 6 to the webs 3 at attachmentpoints 24 is effected by the same process, as is described for thejointing of the webs 3 to the upper and lower skins 1, 2.

What is claimed is:
 1. A pneumatic wing for an aircraft, to be filledwith compressed air, with a leading edge (4) and a trailing edge (5)which comprises an airtight, textile envelope (8), divided into anairtight upper skin (1) forming the upper covering of the wing and anairtight lower skin (2) forming the lower covering of the wing and aplurality of textile webs (3) joining the upper skin (1) and the lowerskin (2), characterised in that: the webs (3) extend longitudinally ofthe wing and are spaced apart across the wing in the direction of airflow dividing the wing into longitudinal cells, the webs (3) beingsecured with the upper skin (1) and the lower skin (2) alonglongitudinal lines of attachment so that forces generated by theinterplay of tensile stress and pressure tensors in the webs (3) and theupper skin (1) and the lower skin (2) give the wing the intended shape;and the wing including air tight cells adapted to change theconfiguration of the wing to include a form selected from the groupconsisting of an aileron, a landing flap, and the height and the shapeof the wing.
 2. A pneumatic wing in accordance with patent claim 1,characterised in that the textile webs (3) are joined to the upper andlower skins (1, 2) by sewing and that the stitches at least are madeairtight following sewing.
 3. A pneumatic wing in accordance with patentclaim 1, characterised in that the textile webs (3), in the area of thejoints, and the upper and lower skins (1, 2) at least in the area of thejoints are laminated with weldable plastics material and the joint isthen made between the upper and lower skins (1, 2) and the textile webs(3) by welding of the joint areas.
 4. A pneumatic wing in accordancewith Patent claim 1, characterized in that an airtight web (6) isconnected between the upper skin (1) and the lower skin (2) spaced fromthe leading edge (4) of the wing, which permits the wing from theleading edge (4) to the airtight web (6) to be under a higher pressurethan the remaining part of the wing.
 5. A pneumatic wing in accordancewith patent claim 1, characterized in that an airtight web (7) issecured between the upper skin (1) and the lower skin (2) spaced fromthe trailing edge (5) of the wing, which permits the wing between theairtight web (7) and the trailing edge (5) to be under a differentpressure than the remaining part of the wing.
 6. A pneumatic wing inaccordance with patent claim 1, characterised in that the textile webs(3, 6, 7) are manufactured from low-stretch material (13), whereby therun of the threads of the fabric (13) is directed essentially paralleland perpendicular to the surface of the wing.
 7. A pneumatic wing inaccordance with patent claim 6, characterised in that the fabric (13) ofa web (3, 6, 7) is doubled at least in the region of the wing root, by afurther fabric (14), whereby the second fabric (14) lies closely ontothe first fabric (13) and is sewn to it together with the lower andupper skin (1, 2), whereby the run of the threads of the second fabricis turned by about 45° in relation to the first fabric (13).
 8. Apneumatic wing in accordance with patent claim 7, characterised in thatmore than one first fabric (13) is provided per web (3, 6, 7).
 9. Apneumatic wing in accordance with patent claim 7, characterised in thatmore than one second fabric (14) is provided per web (3, 6, 7).
 10. Apneumatic wing in accordance with patent claim 1, characterised in thatthe attachment lines of the webs (3) to the upper skin (1) and the lowerskin (2) are found where there is a small variation of the wing profilein the longitudinal direction of the wing, so that they are given by thepoints of contact (10, 11) of locus circles (9) inserted into the wingprofile.
 11. A pneumatic wing in accordance with patent claim 1,characterised in that the attachment lines of the webs (3) to the upperskin (1) and the lower skin (2) are found where there is a largevariation of the wing profile in the longitudinal direction of the wing,so that they are given by the points of contact (10, 11) of locusspheres (26) inserted into the wing profile.
 12. A pneumatic wing inaccordance with patent claim 1, characterised in that the means ofconverting parts of the wing to landing flaps by the application ofcompressed air comprise the addition of a double skin (16, 17) over thearea of the landing flaps to the upper skin (1) and the lower skin (2),which is joined essentially in each case centrally between two webs (3)to the upper skin (1) on the one hand, and to the lower skin (2) on theother hand, whereby between the upper skin (1) and the upper double skin(16) on the one hand, and between the lower skin (2) and the lowerdouble skin (17) on the other hand, channels (19) are formed along thelanding flap region, which can be inflated by compressed air, wherebytheir pressures Δp₂, Δp₃, can deviate from the pressure Δp₁ reigning inthe wing.
 13. A pneumatic wing in accordance with patent claim 1,characterised in that the means of converting parts of the wing toailerons by the application of compressed air comprise the addition of adouble skin (16, 17) over the area of the ailerons to the upper skin (1)and the lower skin (2), which is joined essentially in each casecentrally between two webs (3) to the upper skin (1) on the one hand,and to the lower skin (2) on the other hand, whereby between the upperskin (1) and the upper double skin (16) on the one hand, and between thelower skin (2) and the lower double skin (17) on the other hand,channels (19) are formed along the aileron region, which can be inflatedby compressed air, whereby their pressures Δp₂, Δp₃, can deviate fromthe pressure Δp₁ reigning in the wing.
 14. A pneumatic wing inaccordance with patent claim 12, characterised in that the lower doubleskin (17) extends over a greater number of webs (3) than the upperdouble skin (16).
 15. A pneumatic wing in accordance with patent claim13, characterised in that the upper double skin (16) extends over thesame number of webs (3) as the lower double skin (17).
 16. A pneumaticwing in accordance with patent claim 12 or 13, characterised in that theregion of the pneumatic wing which has double skins (16, 17) encompassesonly a part of the span width of the wing.
 17. A pneumatic wing inaccordance with patent claim 12 or 13, characterised in that the regionof the pneumatic wing which has double skins (16, 17) encompassesessentially the whole the span width of the wing.
 18. A pneumatic wingin accordance with patent claim 1, characterised in that the means ofchanging both the height and also the shape of the wing by theapplication of compressed air comprise that essentially the whole lowerskin (2) of the wing is provided with a double skin (17), essentiallyall the textile webs (3) are manufactured with regions of double wallsso that lengthwise running channels (19) result, which can be inflatedwith compressed air, and that height and shape changing of the wing canbe effected by the combined working of pressure changes in the channels(19) on the underside of the wing and the channels (19) in the webs (3).19. A pneumatic wing in accordance with patent claim 18, characterisedin that the channels (19) in the webs (3) have the same pressure.
 20. Apneumatic wing in accordance with patent claim 18, characterised in thatthe channels (19) in the webs (3) are supplied with different pressures.21. A pneumatic wing in accordance with patent claim 1, characterised inthat in the region of the trailing edge of the wing a part of the wingis similarly constructed to the remainder, however is separated from itin the pressure sense and has a lower pressure, the wing is therebydivided into a carrying wing (31) and an aileron (32), rearmost cells(33) of the carrying wing are joined to foremost cells (34) of theaileron (32) only in a narrow region, however extending over the wholelength of the aileron (32), that an upper actuator (35) and a loweractuator (36) are provided, the upper actuator (35) is fastened to theupper skin (1) of the carrying wing (31) and to that of the aileron (32)over the whole length of the aileron (32), the lower actuator (36) isfastened to the lower skin (2) of the carrying wing (31) and to that ofthe aileron (32) over the whole length of the aileron (32), theactuators (35, 36) each comprise a double skin (37, 38), which arejoined together along longitudinal lines (38) and have channels (19)between the longitudinal lines, which can be inflated with pressure,whereby the actuators (35, 36) shorten in the direction of the air flowof the wing by the application of compressed air.
 22. A pneumatic wingin accordance with patent claims 12, 13, 18, 19, 20, or 21,characterised in that the channels (19) are connected to compressed airlines, through which the pressure in the channels (19) can be matched tothe flight requirements.
 23. A pneumatic wing in accordance with any oneof patent claims 12, 13, 14, 15, 18, or 21, characterised in that thedouble skins (16, 17, 37, 38) are laminated with plastics material so asto be airtight.
 24. A pneumatic wing in accordance with any one ofpatent claims 12, 13, 14, 15, 18, 19, 20, or 21, characterised in thatfor each channel (19) an airtight elastomeric tube (21), hermeticallysealed at each end, is provided, which is positioned lengthwise in thechannel (19) and essentially has the same dimensions as it, a pressuretube (22) opens into the elastomeric tube (21), which can be inflatedwith compressed air thereby, the double skins (16, 17, 37, 38) are notairtight.
 25. A pneumatic wing in accordance with patent claim 12,characterised in that the double skins (16, 17) are sewn to the upperand lower skins (1, 2).
 26. A pneumatic wing in accordance with Patentclaim 12, characterised in that the double skins (16, 17) are welded tothe upper and lower skins (1, 2).
 27. A pneumatic wing for an aircraftin accordance with claim 1 including air permeable webs (3).
 28. Apneumatic wing for an aircraft in accordance with claim 1 includingairtight webs (3).
 29. A pneumatic wing for an aircraft in accordancewith claim 1 where the webs (3) include both air permeable and airtightwebs.
 30. A pneumatic wing for an aircraft in accordance with claim 1where the distance B between webs (3) is essentially proportional to theheight of the wing at each of the webs (3).
 31. A pneumatic wing inaccordance with claim 16, characterized in that the double skins (16,17, 37, 38) are laminated with plastics material so as to be airtight.32. A pneumatic wing in accordance with claim 17, characterized in thatthe double skins (16, 17, 37, 38) are laminated with plastics materialso as to be airtight.
 33. A pneumatic wing in accordance with claim 16,characterized in that for each channel (19) an airtight elastomeric tube(21), hermetically sealed at each end, is provided, which is positionedlengthwise in the channel (19) and essentially has the same dimensionsas it, a pressure tube (22) opens into the elastomeric tube (21), whichcan be inflated with compressed air thereby, the double skins (16, 17,37, 38) are not airtight.
 34. A pneumatic wing in accordance with claim17, characterized in that for each channel (19) an airtight elastomerictube (21), hermetically sealed at each end, is provided, which ispositioned lengthwise in the channel (21) and essentially has the samedimensions as it, a pressure tube (22) opens into the elastomeric tube(21), which can be inflated with compressed air thereby, the doubleskins (16, 17, 37, 38) are not airtight.